I guess my point is that (the way I understand it) the author says that he feels like the web is splitting: on the one hand, those who are fine with the commercial web and ads, even if it means that they probably miss on some stuff that does not get the same marketing power. On the other hand, those who are not fine with it and run ad blockers and privacy tools, even if it means that they miss on some stuff that is only available through surveillance capitalism.

I don't know if we can say that a feeling (which is a descriptive concept) is "extremist". Then the author says that he feels like he is on the side of the ad blockers. Again, I don't see that as extremism. He is not saying "I will never open a commercial website in my life, and I strongly believe nobody should do it". He is saying "well if a commercial website works under my conditions, it's fine, but if they make sure to block me access because I don't want their ads, then I will live without their website".